Lattice girder



May 29, 1962 H. PoTzscH 3,036,676 LATTICE GIRDER Original Filed May 15, 1956 2 Sheets-Sheet 1 INVENTOR HEL MUT Porz s a/ 5J V a A Horney H. POTZSCH LATTICE GIRDER May 29, 1962 Original Filed May is, 1956 2 Sheets-Sheet 2 FIG. 5.

INVENTOR Ham/r Porzsm Q JA @4/ A TTORNEY United States Patent 3,036,676 LATTECE GERBER Helmut Potzsch, Mainz (Rhine), Germany, assignor to Fritz Grebner, Mainz, Germany Continuation of application Ser. No. 584,921, May 15, 1956. This application Sept. 27, 196i), Ser. No. 58,822 Claims priority, application Germany May 18, 1955 Claims. (Cl. 189-37) The present invention relates to lattice girders and structural frameworks suitable as supports for reinforced concrete ceilings and the like.

It is a principal object of this invention to provide a novel lattice girder and framework which may be mechanically mass-produced from simple, commercially available wire and rod materials and which is rigid in at least two supporting planes, such girders serving to construct self-supporting steel frameworks which are static and rigid in at least two dimensions. If desired, the girders of the invention can be made rigid in three dimensions with the same mechanical mass production methods. A structural support framework of this type is capable of carrying loads required in ceiling supports, for instance.

It is another object of the invention to provide a lattice girder of this type, which also includes reinforcing armor for the lateral portions of the concrete footing which carries the hollow ceiling blocks of a ceiling structure.

The above and other objects and advantages are acembedded. By slightly spacing the apexes and ends of adjacent crossties, the girder may readily be cut to any desired length between adjacent crossties without Weakening the girder at that point. Since only two girder elements are arranged one above the other at any point of spot-welding, the girder may be readily mass-produced by longitudinally feeding the elements to the spot-welding station.

from a plurality of three-dimensituated side by side parallel to one steel lattice framework in which the ing at right angles to the longitudinal axis of the girders. With this arrangement, the lattice framework posed of rigid girders arranged parallel to and one another, by being cut up. lattice framework known lattice works, without requiring any greater outlay in material or manufacture.

Such lattice girders and structural steel lattice frame- 2 works may be made either by feeding all the rods or bars in one plane through a spot-welding machine while the previously bent crossties are fed in and fixed in stages and, finally, the longitudinal rods situated in the middle of each individual girder are bent out from the plane together with the corresponding parts of the crossties, thus forming the desired three-dimensional structure, or the feed may be carried out from the beginning in two planes, so that only the pre-bent crossties have to be fed in the first case, in which all the longiverse bars, this distance being reduced when the threedimensional structure is produced.

The above and other features of the invention will be more fully set forth in the detailed description of certain now preferred embodiments thereof, taken in conjunction with the accompanying drawing wherein:

FIG. 1 is a plan view of a girder according to the invention;

FIG. 2 is a side view of the girder according to FIG. 1;

FIG. 3 is a perspective view of the girder according to FIG. 1;

in the transverse direction from one lower boom rod over cross section showing the girder support footing of a ceiling and the diagonals bear against one side only of all the In this way, using previously bent crossties, the girders can in practice be produced continuously and by mechanical means in one operation.

If desired, transverse rods 4 are spot-welded to the boom of crossties or between each crossties. These transverse rods render the girder loadsupporting in three dimensions.

boom rods so that the girder may be cut at any desired point between adjacent transverse elements.

As shown in FIG. 4, when the girder of FIGS. 1-3 is embedded in a concrete footing 5 forming part of a concrete footing which support the hollow ceiling blocks 6.

As is known, the lateral load-carrying portions of the concrete support are subject to r forcement supplied by the crosstie ends is, therefore, of

practical advantage.

The lattice framework illustrated in FIGS. 5 and 6 is composed of the longitudinal rods 1 and 2 and the prebent continuous crossties 3a. In the illustrated embodiment, the arrangement is such that each two longitudinal rods 1 are situated parallel and adjacent one another in a lower plane, while between each pair of said rods 1 a further longitudinal rod 2 is situated in a plane thereabove. The lower rods form the lower boom of individual girders, while the intermediate upper longitudinal rods form the upper boom of girders which are connected together by the continuous transverse crossties 3a.

In the manufacture of the girders or lattice framework, the crossties are fed and spot-welded to the longitudinal rods in such manner that they always bear all against the upper side of the longitudinal booms, as illustrated, in such a Way that no more than two rods lie one on top of the other. The diagonals 3 or 3a are previously bent so that in the main parts of the girder or structural steel lattice framework, triangular meshes are formed so that the two planes of the individual girders which are disposed at an angle relatively to one another constitute rigid, statically determinate and symmetrical planes; asymmetrical support planes can also be formed by suitable pre-bending of the diagonals.

The novel structural steel lattice framework is so constructed that it can be cut up into one or more girders at any time, and the individual parts can be used by themselves for any structural elements, more particularly as ceiling support elements. In the illustrated embodiment it is advantageous to execute the cuts through the transverse connecting pieces in such a way that the girder is formed with two longitudinal rods as a lower boom and one longitudinal rod as an upper boom.

While the invention has been illustrated and described in connection with certain preferred embodiments, it will be clearly understood that many variations and modifications may occur to the skilled in the art after benefiting from the present teaching without departing from the spirit and scope of the invention as defined in the appended claims.

This is a continuation of my application Serial No. 584,921, filed May 15, 1956, now abandoned.

What I claim is:

1. A three-dimensional lattice girder comprising an upper and a lower boom, the upper boom consisting of one longitudinal rod and the lower boom consisting of two longitudinal rods, and a plurality of substantially V- shaped rods constituting crossties each having an apex and two ends which project horizontally outwardly from the lower boom rods, the crossties being arranged in diagonal planes between the upper and lower booms transversely thereof, the apexes of all crossties being spotwelded to the upper side of the longitudinal rod constituting the upper boom and the apexes of adjacent ones of said crossties whose planes are inclined toward each other being slightly spaced from each other, and the two ends of every one of said crossties being spot-welded to the upper side of respective ones of the longitudinal rods constituting the lower boom and the ends of adjacent ones of said crossties whose planes diverge being slightly spaced from each other, and only two girder elements including the rods and crossties being arranged one above the other at the point of spot-welding.

2. A structural framework comprising a plurality of adjacent lattice girders, each girder including an upper and lower boom, each upper boom consisting of one longitudinal rod and each lower boom consisting of two longitudinal rods, the rods being parallel to each other and all the upper booms lying in one plane while all the lower booms lie in a plane spaced therefrom, and a plurality of transverse rods constituting crossties each consisting of a plurality of substantially V-shaped portions integrally interconnected by straight end portions, each V-shaped portion having an apex, the crossties being arranged in diagonal planes between the upper and lower booms transversely thereof, the apexes of all crossties being spot-welded to the upper sides of the longitudinal rods constituting the upper booms and the apexes of adjacent ones of said crossties whose planes are inclined toward each other being slightly spaced apart from each other, and the straight end portions of every one of said crossties being spot-welded to the upper sides of respective ones of the longitudinal rods constituting adjacent ones of said lower booms and the straight end portions of adjacent ones of said crossties whose planes diverge being slightly spaced from each other, and only two girder elements including the rods and crossties being arranged one above the other at the point of spotwelding.

References Cited in the file of this patent UNITED STATES PATENTS 974,891 Lachman Nov. 10, 1910 2,075,874 Stulen Apr. 6, 1937 2,218,197 Hall Oct. 15, 1940 2,284,898 Hartman June 2, 1942 FOREIGN PATENTS 55,782 France May 21, 1952 60,800 France Jan. 26, 1955 1,098,003 France Mar. 2, 1955 177,243 Austria Ian. 11, 1954 UNITED STATES PATENT OFFICE Certificate of Correction May 29, 1962 Patent No. 3,036,676

Helmut Potzsch y certified that error a It is hereb ppems in the above-numbered 1patent requiring correction and that the said Letters Patent should read as corrected be ow.

gs, Sheet 1, FIG. 4 should appear as shown below instead of as in In the drawin the patent:

Signed and sealed this 16th day of October 1962.

Attest DAVID L. LADD, Gammz'ssioner of Patents.

ERNEST W. SWIDER, Attesting Ofiicer. 

